powershell - 如何使用 System.Manangement.Automation.Language... ast

Question

所以我试图为办公室创建一个自定义的 PsAnalyzer 规则，这是我第一次使用$ast 基于命令/变量。结果我有点不知所措。

我一直在使用几个站点来了解[System.Management.Automation.Language]对象类，即this、this和this。

出于测试目的，我正在使用下面的函数 - 看起来很狡猾的参数。

Function IE { 

[cmdletbinding()]

Param( 
    $Url,
    $IEWIDTH  = 550,
    $IeHeight = 450 
)


$IE = new-object -comobject InternetExplorer.Application

$IE.top  = 200 ; $IE.width      = $IEWIDTH ; $IE.height  = $IEHEIGHT
$IE.Left = 100 ; $IE.AddressBar = $FALSE   ; $IE.visible = $TRUE
$IE.navigate( "file:///$Url" )

}

然后使用下面的代码，我希望$IEWIDTH它是唯一失败的参数。

Function Measure-PascalCase {
<#
.SYNOPSIS
The variables names should be in PascalCase.
.DESCRIPTION
Variable names should use a consistent capitalization style, i.e. : PascalCase.
.EXAMPLE
Measure-PascalCase -ScriptBlockAst $ScriptBlockAst
.INPUTS
[System.Management.Automation.Language.ScriptBlockAst]
.OUTPUTS
[Microsoft.Windows.PowerShell.ScriptAnalyzer.Generic.DiagnosticRecord[]]
.NOTES
https://msdn.microsoft.com/en-us/library/dd878270(v=vs.85).aspx
https://msdn.microsoft.com/en-us/library/ms229043(v=vs.110).aspx
https://mathieubuisson.github.io/create-custom-rule-psscriptanalyzer/
#>

[CmdletBinding()]
[OutputType([Microsoft.Windows.PowerShell.ScriptAnalyzer.Generic.DiagnosticRecord[]])]
Param
(
    [Parameter(Mandatory = $True)]
    [ValidateNotNullOrEmpty()]
    [System.Management.Automation.Language.ScriptBlockAst]
    $ScriptBlockAst
)

Process {

    $Results = @()

    try {
        #region Define predicates to find ASTs.

        [ScriptBlock]$Predicate = {
            Param ([System.Management.Automation.Language.Ast]$Ast)

            [bool]$ReturnValue = $false

            if ( $Ast -is [System.Management.Automation.Language.ParameterAst] ){

                [System.Management.Automation.Language.ParameterAst]$VariableAst = $Ast

                if ( $VariableAst.Left.VariablePath.UserPath -eq 'i' ){
                    $ReturnValue = $false
                } elseif ( $VariableAst.Left.VariablePath.UserPath.Length -eq 3 ){
                    $ReturnValue = $false
                } elseif ($VariableAst.Left.VariablePath.UserPath -cnotmatch '^([A-Z][a-z]+)+$') {
                    $ReturnValue = $True
                }

            }

            return $ReturnValue
        }
        #endregion

        #region Finds ASTs that match the predicates.
        [System.Management.Automation.Language.Ast[]]$Violations = $ScriptBlockAst.FindAll($Predicate, $True)

        If ($Violations.Count -ne 0) {

            Foreach ($Violation in $Violations) {

                $Result = New-Object `
                        -Typename "Microsoft.Windows.PowerShell.ScriptAnalyzer.Generic.DiagnosticRecord" `
                        -ArgumentList "$((Get-Help $MyInvocation.MyCommand.Name).Description.Text)",$Violation.Extent,$PSCmdlet.MyInvocation.InvocationName,Information,$Null

                $Results += $Result
            }
        }
        return $Results
        #endregion
    }
    catch {
        $PSCmdlet.ThrowTerminatingError($_)
    }
}
}
Export-ModuleMember -Function Measure-*

相反，我得到：

Line Extent          Message                                                                        
---- ------          -------                                                                        
6 $Url            Variable names should use a consistent capitalization style, i.e. : PascalCase.
7 $IEWIDTH  = 550 Variable names should use a consistent capitalization style, i.e. : PascalCase.
8 $IeHeight = 450 Variable names should use a consistent capitalization style, i.e. : PascalCase.
6 $Url            Variable names should use a consistent capitalization style, i.e. : PascalCase.
7 $IEWIDTH  = 550 Variable names should use a consistent capitalization style, i.e. : PascalCase.
8 $IeHeight = 450 Variable names should use a consistent capitalization style, i.e. : PascalCase.

关于我做错了什么的任何想法？我在这里找到了另一个站点，如果我使用该方法一次测试单个变量，我会得到我期望看到的结果。

为此，请在函数 IE 的末尾添加以下行，

[System.Management.Automation.Language.Parser]::ParseInput($MyInvocation.MyCommand.ScriptContents, [ref]$null, [ref]$null)

然后下面的代码将为您提供长度数字。

$stuffast = .\FunctionIe.ps1

$left = $Stuffast.FindAll({$args[0] -is [System.Management.Automation.Language.AssignmentStatementAst]},$true) 

$left[0].Left.Extent.Text.Length

$left[0].Left.VariablePath.UserPath.Length

标签： powershell

Answer 1

与AssignmentStatementAst具有Left和Right（-hand）值属性的 an 不同，ParameterAst具有NameandDefaultValue属性，因此您需要Name在谓词块中使用：

$predicate = {
    # ...
    if ( $Ast -is [System.Management.Automation.Language.ParameterAst] ) {

        [System.Management.Automation.Language.ParameterAst]$VariableAst = $Ast

        if ( $VariableAst.Name.VariablePath.UserPath -eq 'i' ) {
            $ReturnValue = $false
        }
        elseif ( $VariableAst.Name.VariablePath.UserPath.Length -eq 3 ) {
            $ReturnValue = $false
        }
        elseif ($VariableAst.Name.VariablePath.UserPath -cnotmatch '^([A-Z][a-z]+)+$') {
            $ReturnValue = $True
        }
    }
    # ...
}

或者，翻转您的谓词逻辑以搜索VariableExpressionAst父节点为AssignmentStatementAstor之一的 's ParameterAst：

$predicate = {
  param($ast)

  $ValidParents = @(
    [System.Management.Automation.Language.ParameterAst]
    [System.Management.Automation.Language.AssignmentStatementAst]
  )

  if($ast -is [VariableExpressionAst] -and $ValidParents.Where({$ast -is $_}, 'First')){
    [System.Management.Automation.Language.VariableExpressionAst]$variableAst = $ast

    # inspect $variableAst.VariablePath here
  }

  return $false
}